I have probably rebuilt at least 75 motors in my life for myself,friends and customers,the oil rings have always had thoes little plastic square colored pieces near the ends of the expanders. I have always thought they were there to keep idiots from overlapping rings or so they could identify where the end of the expander was. What real purpose do they serve? On my 540 I'm in the process of tearing down to freshen I'm finding the plastic is broke off and floating around near its original location,kinda trapped in the oil ring not hurting anything but definately not something that needs to be flying around inside my motor either. I'm looking fwd to hearing everyones opinion or answer on this one,Smitty

On all 8 holes?Are the other rings OK? BOB

I'm old and forgetful, so I don't remember what they do. My engine builder told me to remove them before installing the pistons for exactly the reason you found- he felt they could cause problems with the oil control ring. So my engine now has 4 seasons on it with no problems, n/a 540, so I say remove them.

I also thought to keep the ring from overlapping and they would somehow disinegrate after ran. Never tore down a motor I rebuilt to see if they were still there though.

All 8 pistons had the little plastic pieces on the oil ring expanders just floating around and even wore down from rubbing on the cylinders. They really didn't hurt anything but I have never seen them things get loose before either. I can see taking a pick and prying them out in the future I can't see what purpose they would serve other than to help you see where the expander end is,Smitty

They are there so the the expander doesn't overlap during assembly. Don't worry about them. I assemble them and install them on the expander. I've only seen one come off. They don't scuff or bother anything.

I had them break loose on all 8 sets of oil rings,never seen that before,it didn't hurt anything but I don't like the idea of pieces floating around in the rings,Smitty